In communications systems, such as wireless, wireline, LAN, WAN, WIMAX, Blue Tooth wireless mobile communications systems, etc., various resources or pools of resources are shared among multiple devices that require access to or continued utilization of the shared resources. Examples of such shared resources include communications network elements, base stations, networks, servers, communications media, etc. Resource contention can occur when multiple devices attempt to simultaneously access a resource such that the input handling capacity of the resource is exceeded (access attempt collision failure), or when the resource is operating at maximum capacity and is unable to service any additional information from one or more devices (utilization attempt failure). For instance, to initiate a call in an Evolution Data Only (EVDO) Rev. A wireless network, mobile communications devices, such as cell phones, PDAs, portable computers, etc., compete for access to a local base station serving a given area or location to communicate with the base station over an access channel. In this case, the base station periodically sends a broadcast message to all devices in the area, which identifies the access channel to be used for setting up a call. Contention arises when two or more mobile units simultaneously attempt to access the base station on the access channel, leading to a collision of the call initiation messages. Resource utilization contention occurs when contention for a shared resource with limited utilization or loading capabilities causes some attempts for utilization to fail (e.g., dropped data packets). In many of these systems, moreover, access to the resource is provided in prioritized fashion according to the class of the devices attempting usage of the resource. For instance, EVDO Rev. A and other communications systems support two or more levels or classes of device priority, with devices of a higher priority class receiving preferential utilization or access relative to lower priority devices.
In systems having shared resources, it is often desirable to ascertain the amount of access/utilization attempts (incoming throughput seen by the resource) in a given time period, for data monitoring and/or system control purposes. In this regard, many shared resource systems allow devices to retry failed access attempts in a controlled manner (sometimes referred to as apersistence) according to a system controlled parameter, in order to optimize resource access/utilization throughput and/or to minimize access latency. For example, the devices that experience a failure in attempting access/utilization may perform an apersistence test using apersistence property information received from the resource of contention. In the case of EVDO systems, the communications devices are synchronized with a base station resource to selectively attempt access/utilization at discrete times, where the devices internally perform an apersistence test using an apersistence property value broadcast by the base station. The devices derive an apersistence number from the apersistence property value received from the base station, and compare the apersistence number to a randomly generated value in each access cycle, and the decision on whether to attempt access/utilization by the device is therefore based on information received from the resource. In order to control the access attempts, the base station resource adjusts the value of the apersistence property in closed loop fashion to reduce the likelihood of a given device passing the apersistence test when the current resource load is high and vice versa. However, the accuracy of the closed loop adjustments to the apersistence property value is limited by the extent to which the actual current resource load is observable. Furthermore, the ability to compile statistics of access/utilization attempts with respect to a given shared resource is likewise dependent upon the accuracy of the resource loading measurements. In addition, it may be desirable to ascertain the rate of access/utilization attempts associated with a given class of requesting devices in a multiple class system. Consequently, there is a need for techniques and apparatus for estimating the rate of access/utilization attempts for resources of contention.